This invention relates to a digital filter and, particularly, to a digital filter used for an image processing.
Digital filters such as convolution (convolutional processing) filter and the like filters have heretofore been used for an image processing.
FIG. 9 is a diagram illustrating the constitution of a conventional digital filter which includes delay units 910, 911, coefficient multiplier units 920, 921, 922 and adder units 930, 931. In this digital filter, an input signal and a signal obtained by delaying the input signal are multiplied by a predetermined coefficient, and an added result thereof is produced as an output signal.